Downhole vibration apparatus and methods

Abstract

A method of extending an earthen bore comprises the steps of rotating a drill bit at the end of a tubular while vibrating the tubular. The method results in reduced friction to tubular advance through the bore and results in stabilized drill bit loading and longer usable drill bit life. A method of conditioning a cement slurry in an annulus between a casing and a bore to improve a resulting cement liner comprises the steps of coupling a vibration generator to the casing, running the casing into the bore, displacing the cement slurry into the annulus and using the vibration generator to vibrate the casing. A vibration generator may comprise a mass, having a mass center, coupled to a frame, a motor and a power source to spin the mass about an axis offset from the mass center.

1 . A method of advancing a tubular through a highly deviated portion of an earthen bore comprising the steps of:
 coupling a vibration generator to a tubular;   running the tubular into the bore to dispose the vibration generator within the highly deviated section; and   activating the vibration generator to vibrate a portion of the tubular within the highly deviated section of the bore.   
   
   
       2 . The method of  claim 1  further comprising the steps of:
 coupling a drill bit to the tubular; and   rotating the drill bit against an end of the bore.   
   
   
       3 . The method of  claim 2  wherein the tubular is a drill string. 
   
   
       4 . The method of  claim 2  wherein the step of rotating the drill bit against the end of the bore comprises the steps of:
 coupling a mud motor to the drill bit; and   providing a flow of pressurized fluid to the mud motor to rotate the drill bit.   
   
   
       5 . The method of  claim 1  wherein the step of coupling a vibration generator to a tubular comprises the steps of:
 coupling a mass having a mass center to the tubular;   coupling a motor to the mass;   coupling a power source to the motor; and   activating the motor to spin the mass on an axis offset from the mass center.   
   
   
       6 . The method of  claim 1  further comprising the steps of:
 coupling a float device to the tubular;   displacing a volume of cement slurry through the tubular and the float device and into an annulus between the tubular and the bore; and   conditioning a portion of the volume of cement slurry within the highly deviated section.   
   
   
       7 . The method of  claim 1  further comprising the steps of:
 coupling a second vibration generator to the tubular;   disposing the second vibration generator within the highly deviated section; and   activating the second vibration generator to vibrate a second portion of the tubular within the highly deviated section of the bore.   
   
   
       8 . The method of advancing a tubular through a highly deviated section of an earthen bore comprising the steps of:
 coupling a mass having a mass center to a tubular;   coupling a motor to the mass;   coupling a power source to the motor;   running the tubular into the earthen bore to position the mass within the highly deviated section of the bore; and   spinning the mass on an axis offset from the mass center to vibrate a portion of the tubular adjacent the mass.   
   
   
       9 . The method of  claim 8  wherein the power source is a battery and the motor is an electrically-driven motor. 
   
   
       10 . A method of extending an earthen bore comprising the steps of:
 coupling a drill bit and a vibration generator to a tubular;   running the tubular into the bore;   rotating the drill bit against an end of the bore; and   vibrating the tubular using the vibration generator.   
   
   
       11 . The method of  claim 10  further wherein the step of vibrating the tubular using the vibration generator comprising the steps of:
 coupling a mass having a mass center to a tubular sub;   coupling a motor to the mass;   coupling a power source to the motor; and   activating the motor to spin the mass about an axis offset from the mass center.   
   
   
       12 . The method of  claim 10  wherein the step of rotating the drill bit against the end of the bore comprises the step of:
 fluidically driving a mud motor to rotate the drill bit relative to the tubular.   
   
   
       13 . The method of  claim 10  further comprising the step of:
 coupling a second vibration tool to the tubular; and   vibrating the tubular using the second vibration tool.   
   
   
       14 . A method of conditioning a volume of cement slurry disposed within an annulus between a tubular and an earthen bore into which the tubular is run, comprising the steps of:
 coupling a vibration generator to the tubular;   displacing the volume of cement slurry through the bore of the tubular and into the annulus; and   activating the vibration generator to vibrate the volume of cement slurry.   
   
   
       15 . The method of  claim 14  wherein the step of coupling a vibration generator to the tubular comprises the steps of:
 rotatably coupling a mass having a mass center to the tubular; and   coupling a motor to the mass;   coupling a power source to the motor; and   activating the motor to spin the mass on an axis offset from the mass center.   
   
   
       16 . The method of  claim 15  further comprising the step of coupling a float device to the tubular. 
   
   
       17 . The method of  claim 16  wherein the float device is at least one of a float collar and a float shoe. 
   
   
       18 . The method of  claim 17  wherein the float device comprises a check valve. 
   
   
       19 . The method of  claim 14  wherein the step of coupling a vibration generator to the tubular comprises the steps of:
 providing a sub having a first threaded connection at a first end coupled to the tubular, a second threaded connection at a second end, and a fluid passage therebetween in fluid communication with the bore of the tubular.   
   
   
       20 . The vibration tool of  claim 14  wherein the sub further comprises a second threaded connection at a second end of the fluid passage. 
   
   
       21 . The vibration tool of  claim 14  wherein the sub further comprises a float shoe having a valve.